Study On Vibration Characteristics And Optimal Control Of Steering System Based On Transfer Path Method

The vibration of the steering wheel in a certain light truck is too large,and the performance of NVH can not meet the design requirements.In order to identify the exciting source,the energy transfer path and analyze the mechanism of steering wheel vibration accurately,the transfer path analysis(TPA)is applied to study the steering system.In order to avoid the most complicated decoupling between substructures in normal sequence research,the inverse substructure analysis method is applied to TPA method.It is more simple and easy to obtain the uncoupled transmission characteristics of the powertrain mounting to the steering wheel and the non-coupled dynamic stiffness characteristics of the powertrain mounting Then the suspension dynamic stiffness method is applied to the condition load identification,and the order of contribution of the energy transfer is analyzed and sorted.Then doing further research on the vibration characteristics of the steering system Avoiding the system decoupling work and suspension dynamic stiffness test experiment,which greatly improved the experimental efficiency.In the second chapter,the paper summarizes the vibration principle of the steering system(including steering wheel)during idling,establishes the steering wheel vibration transfer model and introduced the vibration evaluation index.The third chapter is derived from the theoretical formula,established the relationship between powertrain mounting and the dynamic characteristics of the steering wheel,and gives the concrete expression between them.Accordingly,the fourth chapter obtains the frequency response function of 12 uncoupled transmission paths through testing and calculation.Combined with the uncoupled load of each path estimated by the method of suspension dynamic stiffness,the energy transfer characteristics of 12 paths are calculated.Steering wheel measuring point response to large main path and possible influencing factors are summarized and analyzed.In the fifth chapter,through the powertrain mount optimization and structural rigidity test and modal test of the steering system components,the steering system design is optimized.Through testing,it shows that the NVH performance of the steering system achieves the expected improvement goal.In this paper,a detailed and systematic dynamical research method and a related structural dynamics testing procedure are established for the steering system,and the feasibility of applying the inverse substructure method to the vibration transfer path analysis of the vehicle steering system is verified again.The successful finding of the path of maximum contribution not only points the direction for the subsequent optimization of the steering system,but also provides new methods and new ideas for researchers who study the powertrain mounting and the vibration characteristics of other vehicle systems.